title: Assessment of enamel damage after removal of ceramic brackets.
abstract: BACKGROUND
  Since the introduction of ceramic brackets, research has been performed to evaluate enamel damage caused during their removal. One problem in comparing treated and control groups is the absence of assurance that the surfaces were undamaged before the brackets were bonded and debonded, or that superficial treatment applied to the enamel could hinder damage detection. The aim of this in-vitro study was to evaluate enamel injuries during debonding of 3 types of ceramic brackets.
  
  
  METHODS
  Forty-five premolars, extracted for orthodontic purposes, were divided into 3 groups of 15. The enamel surfaces were photographed with a magnifying loupe (60 times) in an optical stereomicroscope (Stemi 2000-C, Zeiss, Oberkochen, Germany) with a digital camera. A different type of backet was bonded and debonded in each group: mechanical retention, mechanical retention with a polymer base, and chemical retention. After debonding, the surfaces were again photographed. The photographs were evaluated for quality of enamel surface according to a predetermined scale. The results were tested by method error and the chi-square test.
  
  
  RESULTS
  The damage evaluation comparing the same surface before bonding and after debonding showed no significant statistical difference between the mechanical retention group and the polymer base retention group. There was a significant statistical difference (P <0.05) for the chemical adhesion ceramic bracket group.
  
  
  CONCLUSIONS
  The difference between the enamel surfaces before bonding and after debonding brackets with chemical retention was statistically significant; bonding and debonding these brackets resulted in enamel damage.
authors.affiliation: Fluminense Federal University, Niterói, Rio de Janeiro, Brazil. flaviamitiko@yahoo.com.br
authors.forename: Flávia Mitiko Fernandes
authors.initials: FM
authors.lastname: Kitahara-Céia
authors.forename: José Nelson
authors.initials: JN
authors.lastname: Mucha
authors.forename: Paulo Acioly
authors.initials: PA
authors.lastname: Marques dos Santos
mesh_terms: D000269:Adhesives / Q000009:adverse effects; D002516:Ceramics; D017005:Dental Debonding / Q000009:adverse effects*; D003743:Dental Enamel / Q000293:injuries*; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets
chemical_list: D000269:Adhesives